1. Computer Networks A.S. Tanenbaum 5 th Edition 2011 Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

2. Introduction Chapter 1 Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

3. Computer Network A large number of separate but interconnected computers. A collection of autonomous computers interconnected by a single technology. Two computers are interconnected if they are able to exchange information. A collection of computers interconnected by a single technology. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

4. Business Applications (1) A network with two clients and one server Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

5. Business Applications (2) The client-server model involves requests and replies Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

6. popular uses of the Internet for home users 1. Access to remote information. 2. Person-to-person communication. 3. Interactive entertainment. 4. Electronic commerce.

7. Applications (1) In a peer-to-peer system there are no fixed clients and servers, no central database. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

8. Applications (2) Some forms of e-commerce Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

9. Mobile Users Combinations of wireless networks and mobile computing Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

10. Network Hardware (1) Broadcast Link Point-to-Point Link Point-to-Multipoint 10

11. Link Types

12. Personal Aria Network

13. Local Aria Network

14. Wide Aria Network

16. Network Software Networks are usually connected together to make inter-networks. Internet is the most well-known inter-network. Gateway: A machine that makes connection between two or more networks and provide the necessary translation. Gateways are distinguished by the layer at witch they operate. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

17. Protocol Hierarchies (1) Layers, protocols, and interfaces. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

18. Protocol Hierarchies (2) The philosopher-translator-secretary architecture Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

19. Protocol Hierarchies (3) Example information flow supporting virtual communication in layer 5. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

20. Connection-Oriented Versus Connectionless Service Six different types of service. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

21. Service Primitives (1) Six service primitives that provide a simple connection-oriented service Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

22. Service Primitives (2) A simple client-server interaction using acknowledged datagrams. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

23. The Relationship of Services to Protocols The relationship between a service and a protocol. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

24. The OSI Reference Model Principles for the seven layers Layers created for different abstractions Each layer performs well-defined function Function of layer chosen with definition of international standard protocols in mind Minimize information flow across interfaces between boundaries Number of layers optimum Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

25. The OSI Reference Model The OSI reference model Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

26. OSI Reference Model Layers Physical layer Data link layer Network layer Transport layer Session layer Presentation layer Application laye r Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

27. The TCP/IP Reference Model Layers Link layer Internet layer Transport layer Application layer Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

28. The TCP/IP Reference Model (1) The TCP/IP reference model Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

29. The TCP/IP Reference Model (2) The TCP/IP reference model with some protocols we will study Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

30. The Model Used in this Book The reference model used in this book. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

31. Comparison of the OSI and TCP/IP Reference Models Concepts central to OSI model Services Interfaces Protocols Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

32. Critique of the OSI Model and Protocols Bad timing. Bad technology. Bad implementations. Bad politics. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

33. OSI Model Bad Timing The apocalypse of the two elephants. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

34. Example Networks Internet ARPANET NSFNET Third-generation mobile phone networks Wireless LANs: 802.11 RFID and sensor networks Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

35. The ARPANET (1) a)Structure of the telephone system. b)Baran’s proposed distributed switching system. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

36. The ARPANET (2) The original ARPANET design Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

37. The ARPANET (3) Growth of the ARPANET. a)December 1969. b)July 1970. c)March 1971. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

38. The ARPANET (4) Growth of the ARPANET. d)April 1972. e)September 1972. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

39. Architecture of the Internet Overview of the Internet architecture Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

40. Third-Generation Mobile Phone Networks (1) Cellular design of mobile phone networks Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

41. Third-Generation Mobile Phone Networks (2) Architecture of the UMTS 3G mobile phone network. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

42. Third-Generation Mobile Phone Networks (3) Mobile phone handover (a) before, (b) after. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

43. Wireless LANs: 802.11 (1) (a)Wireless network with an access point. (b)Ad hoc network. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

44. Wireless LANs: 802.11 (2) Multipath fading Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

45. Wireless LANs: 802.11 (3) The range of a single radio may not cover the entire system. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

46. RFID and Sensor Networks (2) Multihop topology of a sensor network Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

47. Network Standardization Who’s Who in telecommunications Who’s Who in international standards Who’s Who in internet standards Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

48. Who’s Who in International Standards (1) The 802 working groups. The important ones are marked with *. The ones marked with  are hibernating. The one marked with † gave up and disbanded itself. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

49. Who’s Who in International Standards (2) The 802 working groups. The important ones are marked with *. The ones marked with  are hibernating. The one marked with † gave up and disbanded itself. Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

50. Metric Units (1) The principal metric prefixes Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

51. Metric Units (2) The principal metric prefixes Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011

52. End Chapter 1 Computer Networks, Fifth Edition by Andrew Tanenbaum and David Wetherall, © Pearson Education-Prentice Hall, 2011